Replaceable, gamma sterilizable Coriolis flow sensors

ABSTRACT

A Coriolis flow sensor includes a metal flow tube and an enclosure. The enclosure encloses the flow tube and is constructed at least partially from a gamma transparent material. The metal flow tube may be constructed from stainless steel. The gamma transparent material and the flow tube are thin enough to permit sterilization of an interior of the flow tube by gamma irradiation of the flow tube through the gamma transparent material. The enclosure is also shaped to facilitate locking and unlocking the Coriolis flow sensor in place on a mounting structure.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/523,185, “Heavy Cradle For Replaceable Coriolis FlowSensors,” filed Nov. 10, 2021; which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 63/274,841, filedNov. 2, 2021. This application is also a continuation-in-part of U.S.patent application Ser. No. 17/702,554, “Coriolis Mass Flow SensorsHaving Different Resonant Frequencies,” filed Mar. 23, 2022; which is acontinuation of U.S. patent application Ser. No. 16/846,061, “CoriolisMass Flow Sensors Having Different Resonant Frequencies,” filed Apr. 10,2020. The subject matter of all of the foregoing is incorporated hereinby reference in their entirety.

BACKGROUND 1. Technical Field

This disclosure relates generally to Coriolis flow sensors.

2. Description of Related Art

Many applications require the controlled flow of fluids. A flow processsystem usually includes a number of flow sensors to measure the flowrate of fluids. Coriolis flow sensors measure the flow rate of fluidsbased on vibrations caused by the Coriolis effect of fluid flowingthrough the sensor. However, in order to reduce cross-talk ordestructive interference effects, conventional flow sensors may beattached to a large mass and the flow sensor itself may be constructedfrom heavy or thick materials.

However, these conventional designs can be expensive and are notsuitable for single use or disposable applications. Also, sterilizationof flow sensors having metal enclosures or metal components is typicallyimplemented by using chemicals, which is not as effective and can causecross-contamination of the flow sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure have other advantages and features whichwill be more readily apparent from the following detailed descriptionand the appended claims, when taken in conjunction with the examples inthe accompanying drawings, in which:

FIG. 1 shows a Coriolis flow sensor.

FIG. 2 shows a Coriolis flow sensor inserted into a correspondingcradle.

FIG. 3 shows a test setup to verify sterilization of a Coriolis flowsensor using gamma irradiation.

FIG. 4A shows a perspective view of a Coriolis flow sensor and acorresponding cradle.

FIG. 4B shows a cross section view of the Coriolis flow sensor.

FIG. 4C shows a perspective view of the Coriolis flow sensor locked intothe cradle.

FIG. 4D shows top, front and side views of the Coriolis flow sensorlocked into the cradle.

FIGS. 5A and 5B show top perspective and bottom perspective views of thecradle.

FIG. 6 shows the cradle attached to a skid.

FIGS. 7A and 7B show perspective views of another embodiment of aCoriolis flow sensor and corresponding cradle.

FIGS. 8A and 8B show perspective views of yet another embodiment of aCoriolis flow sensor and corresponding cradle.

FIGS. 9A and 9B show perspective views of yet another embodiment of aCoriolis flow sensor and corresponding cradle.

FIG. 10 is a diagram of a flow measurement system containing Coriolisflow sensors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The figures and the following description relate to preferredembodiments by way of illustration only. It should be noted that fromthe following discussion, alternative embodiments of the structures andmethods disclosed herein will be readily recognized as viablealternatives that may be employed without departing from the principlesof what is claimed.

FIG. 1 shows a Coriolis flow sensor 150. The Coriolis flow sensor 150 isa device that measures the flow rate of a fluid based on vibrationscaused by the Coriolis effect of the fluid flowing through the sensor.The flow sensor 150 includes an inlet (hidden in FIG. 1 ), a flow tube154 (or two or more flow tubes in some designs) and an outlet 156. Thisprovides a flow path for a fluid through the flow sensor 150. The flowtubes 154 can vibrate, for example as driven by magnets and coils 157.As the fluid flows through the flow tubes 154, Coriolis forces produce atwisting vibration of the flow tubes, resulting in a phase shift in thevibration of the flow tubes. The fluid flow also changes the resonantfrequency of the flow tubes. The flow sensor 150 includes transducersthat generate electrical signals that are sensitive to the phase shiftand/or change in resonant frequency. These signals may be processed todetermine the mass fluid flow rate and/or density of the fluid.

It is desirable for the Coriolis flow sensor to have good accuracy overa broad operating range. As a result, the flow tubes may be constructedfrom materials with a high Young's modulus (tensile modulus), forexample a Young's modulus of at least 50 GPa. The flow tubes may bemetal flow tubes. They may be constructed from stainless steel, such as316, 316L, 304 or 304L stainless steel. Other possible metals includeHastelloy, monel, nickel, titanium, and tantalum. Non-metals may also beused, such as zirconium. Table 1 tabulates Young's modulus for a numberof different materials.

TABLE 1 Young's modulus for different materials Material Young's modulus(GPa) Steel, stainless 304, 304L, 193 316, or 316L Tantalum 186 Titanium116 Titanium alloy 110 Hastelloy 205 Monel metal 179 Zirconium 94.5

The Coriolis flow sensor may have an operating range that ranges from 25ml/min, or 20 ml/min or 15 ml/min or less on the low side, up to 4000ml/min or 5000 ml/min or more on the high side, for ¼″ diameter flowtubes. Operating ranges will be different for different size flow tubes.2″ diameter flow tubes may have operating ranges up to 350 l/min ormore. The operating range may be characterized by a turndown ratio,which is the ratio of the maximum flow rate divided by the minimum flowrate. The flow sensor may have an accuracy of +/−1% of the actual flowrate over the operating range.

The Coriolis flow sensor is designed to be disposable or single use.Accordingly, the tubes 154 are enclosed in an enclosure 130. Theenclosure 130 may be locked and unlocked in place on a mountingstructure, as shown in FIG. 2 . FIG. 2 shows a Coriolis flow sensor 150locked into place in a cradle 100. Handles 159 may be used to insert theflow sensor 150 into the cradle 100, and to remove the flow sensor fromthe cradle. The inlet 152 and outlet 156 are visible in FIG. 2 , but theflow tubes are not visible since they are within the cradle 100. In thisexample, the locking mechanism is four thumb screws 142. The enclosure130 is shaped to slide into and out of the cradle 100.

The Coriolis flow sensor 150 is also designed to permit sterilization bygamma irradiation. Parts of the enclosure 130 are constructed from gammatransparent material, which are materials that have low attenuation ofgamma irradiation. In FIG. 1 , the side panels 135 are polycarbonate orother types of plastic. As a result, the interior of the flow tube 154may be sterilized by gamma irradiation. The side panel 135 is thinenough and the walls of the flow tube 154 are thin enough to allowsufficient gamma irradiation to reach the inside of the flow tube. Forexample, the side panel 135 may be polycarbonate which readily passesgamma irradiation and the flow tubes may have a wall thickness notgreater than 0.020″. The wall thickness will vary depending on the sizeof the flow tubes. Table 2 below shows wall thicknesses for differentsize seamless stainless flow tubes. Maximum wall thicknesses may beapproximately two times what is shown in Table 2.

TABLE 2 Wall thickness for different size flow tubes Outer diameter offlow tube Wall thickness (inches) (inches) 1/4″ 0.020 3/8″ 0.028 1/2″0.035 3/4″ 0.035 1″ 0.049 2″ 0.065

The Coriolis flow sensor 150 also includes memory used to storecalibration data or other types of data for the Coriolis flow sensor. Ifgamma sterilization is used, this memory may be gamma stable memory.

FIG. 3 shows a test setup to verify sterilization of a Coriolis flowsensor using gamma irradiation. For clarity, FIG. 3 shows only the flowtube 154 and not the enclosure 130. Gamma dosimeters are placed insidethe flow tube 154 at the locations shown. The Coriolis flow sensor,including the plastic enclosure 130, is irradiated by gamma irradiation.The dosimeters indicate that sufficient radiation reaches the interiorof the flow tube 154 to sterilize the flow sensor. The plastic walls ofthe enclosure 130 and walls of the flow tube 154 are thin enough to passsufficient gamma irradiation.

In some designs, the Coriolis flow sensor may also be sterilized byother methods: ethylene oxide cleaning, sodium hydroxide cleaning orx-ray sterilization for example. If the Coriolis flow sensor is usedmultiple times (e.g., multi-use applications or continuous useapplications), it may be sterilized between uses. To avoid having toremove the Coriolis flow sensor, it may be designed for clean-in-placeprocesses or steam-in-place processes. Thus, the same flow sensor may besuitable for use in single-use applications, in multi-use applicationsand in continuous use applications.

The figures show examples of Coriolis flow sensors, but it should beunderstood that other types of Coriolis flow sensors may also be used.The number and shapes of tubes, the material and construction of thetubes and flow sensor, and the arrangement of the inlet and outlet mayall be changed depending on the specific design of the Coriolis flowsensor. The Coriolis flow sensor may include one flow tube, or two ormore flow tubes. The flow tubes may have different shapes in differentflow sensors: a U-tube, a V-tube, an omega tube, or a straight tube, forexample. Typically, Coriolis flow sensors are sized with connectionsfrom 1/16″ to 2″ hose barbs or tri-clamp fittings. Other types offittings may also be used on Coriolis flow sensors. Typical flow rangesof these flow sensors range from 0.05 gm/min to 0.5 gm/min for thesmallest ( 1/16″ hose barb connections) size to 10 kg/min to 350 kg/minfor the largest (2″) size. Typical accuracies range from 0.1% to 1.0% ofactual reading.

FIGS. 4-5 show different views of example embodiments of a Coriolis flowsensor 150 and corresponding cradle 100. FIG. 4 shows both the Coriolisflow sensor 150 and the cradle 100, where FIG. 4A is an exploded view,FIG. 4B shows just the flow sensor, FIG. 4C shows the assembled system,and FIG. 4D shows top, front and side views of the assembled system.FIGS. 5A and 5B are perspective views that show just the cradle 100 andlocking mechanism 140.

The flow sensor 150 can be seen in cross section in FIG. 4B. The flowsensor 150 includes an inlet 152, a flow tube 154 (or two flow tubes insome designs) and an outlet 156. Because Coriolis flow sensors operatebased on changes in the vibration of the flow tubes, vibration effectsthat are caused by sources other than the fluid flow may introduceinaccuracies. For example, if the flow sensor and other devices aremounted on a common support structure, then vibrations from pumps andother devices may mechanically couple to the flow sensor through thesupporting structure. The vibration of the flow tubes may also bedistorted or otherwise changed through resonant coupling to thesurrounding support structure.

Zero drift is one such effect. Coriolis flow sensors are electricallypowered on, even when they are not measuring flow. So when there is noflow being pumped or flowing through the Coriolis Flow tubes, the tubescontinue to vibrate. Sometimes these tubes are empty and sometimes thereis liquid in these tubes. Zero drift is a phenomenon which shows someminimal flow rate occurring when there is no real actual flow. Oneinstance of zero drift is when there is dormant fluid left in theCoriolis flow tubes and a certain amount of sloshing occurs. Thisminimal flow rate is very small and is usually a very small percentageof the minimum flow rate of each Coriolis flow sensor. In addition,vibrations from external mechanical devices such as pumps and valvesalso cause zero drift by interfering with the analog or digital outputsignal from a Coriolis flow sensor by contributing to it.

One way to reduce zero drift is to increase the mass of the flow sensor.More mass dampens out external mechanical vibrating interferences andalso the sloshing of dormant liquid will be subdued due to heavier mass.

However, in some applications, the Coriolis flow sensors are notpermanent. They are intended to be replaced fairly regularly. They mayeven be single use or considered to be disposable. Single use ordisposable Coriolis flow sensors are used in the bio-pharmaceutical andpharmaceutical industries to manufacture vaccines including vaccines forCovid-19, active pharmaceutical ingredients for cell and gene therapyand nuclear medicine manufacturing.

In these cases, it is desirable to make the Coriolis flow sensor aslightweight and inexpensive as possible, so making a large and massiveCoriolis flow sensor is not desirable. In addition, some applicationsmay also require the sterilization of flow sensors. Gamma irradiationmay be used to sterilize the flow sensor, in which case the flow sensoris constructed from materials that are gamma irradiatable, for exampleto a minimum of 25 kGy or 50 kGy or 65 kGy which may be the irradiationlevels used for sterilization in certain bio-pharma applications.

In the examples shown herein, the effective mass of the Coriolis flowsensor 150 is increased by locking it to a heavy cradle 100 when it isin use. The cradle 100 has a mass that preferably is at least 10 to 30times the mass of the Coriolis flow sensor. For example, typicalCoriolis flow sensors may have masses in the range of 0.2 kg˜3 kg andtypical mass for the heavy cradle may then be 5 kg˜80 kg.

The cradle 100 has a mounting structure 114 (see FIG. 5A) for theCoriolis flow sensor 100, and a locking mechanism 140 is used to lockand unlock the Coriolis flow sensor in place on the mounting structure.The locking mechanism produces sufficient locking force when locked thatthe Coriolis flow sensor 150 and cradle 100 (as shown in FIG. 4A)vibrate together as a unitary body.

In the example of FIGS. 4-5 , the cradle 100 includes a rectangularmetal collar 110 which accounts for a significant amount of the mass ofthe cradle. The collar 110 has a rectangular aperture with an interiorlip 114, which is most visible in FIG. 5 . The lip is also rectangularand annular in shape. The flow sensor 150 includes a plastic housingwith a ridge 158. The ridge 158 fits into the aperture of the metalcollar 110 and presses against the lip 114 shown in FIG. 5A. The lockingmechanism 140 applies force to the ridge 158 to hold the ridge rigidlyagainst the lip 114. The flow tubes 154 protrude through the annularopening in the lip 114.

In this example, the locking mechanism 140 uses thumb screws 142 tocreate the force. When tightened, the thumb screws 142 apply pressure totongues 144, which in turn press the ridge 158 against the interior lip114 of the metal collar 110. The thumb screws are designed to apply aspecific amount of force. In the example shown, the force is applied atfour locking points arranged in a rectangular shape, although otherarrangements are also possible. The applied force should be large enoughto adequately reduce vibration of the flow sensor 150 relative to thecollar 110. As a result, the flow sensor 150 and cradle 100 will vibrateas a unitary body and the cradle 100 will effectively increase the massof the flow sensor 150, rather than the two vibrating relative to eachother. For example, each of the thumb screws 142 may apply 3Newton-meters (Nm) of force or more, to hold the flow sensor 150 andcradle 100 rigidly relative to each other. This is an aggregate force of12 Nm or more for all of the thumb screws. In other designs, lowerlocking forces may be acceptable, for example 10 Nm or more, or 5 Nm ormore.

Applying uniform force is also important. Applying the same force at thefour locking points allows for the pressure applied to be balanced. Ifthe forces at the different locking points were not the same, the sensorwould be imbalanced and the zero drift and resulting inaccuracy would behigher. In FIGS. 4-5 , the same amount of force should be applied toeach locking point. For example, the force applied at each of thelocking points may be within 15% of each other, or more preferablywithin 10%, within 5% or even within 1% of each other.

One advantage of using thumb screws 142 is that the locking mechanismmay be operated manually. The thumb screws 142 may be loosened, thetongues 144 rotated or swiveled away to release the flow sensor 150, andthe flow sensor removed and replaced with another flow sensor. Thisfacilitates the replacement of flow sensors, including disposable andsingle use flow sensors. In some single use or disposable applications,the flow sensors may be removed and replaced in one minute or less.

The cradle 100 also includes enclosure 120, which encloses the rest ofthe Coriolis flow sensor. The enclosure also adds mass. The enclosureshown in FIGS. 4-5 includes a cable hole 122 (see FIG. 5B) to allowpower and data connections to the flow sensor for sensors with rearconnecting cables. FIG. 1 shows a top mounting cable connection.

FIG. 6 shows the cradle 100 attached to a skid 670. A skid is amechanical framework on which equipment may be mounted. In this example,the cradle 100 is attached to a metal plate or panel 675, which isattached to the skid 670. A vibration dampening gasket 680 is positionedbetween the cradle 100 and the plate 675. In the vertical direction, thecradle 100 is supported by cross members 677A (an L bracket) and 677B (across beam of the skid). Vibration dampening gaskets 687A and 687B arepositioned between the cradle 100 and the cross members 677A and 677B.

Note that the heavy cradle 100 does not make direct contact with anypart of the skid 670. It is always separated by vibration gaskets 680,687. The gaskets 680, 687 provide vibration isolation between the cradle100 and the skid 670 (and other components mounted on the skid). Forexample, the vibration gaskets may significantly dampen low frequencyvibrations.

The heavy cradle 100 adds mass to the Coriolis flow sensor 150, and thevibration gaskets 680, 687 isolate the cradle and flow sensor from therest of the flow process system. As a result, zero drift is reduced. Forexample, for smaller size sensors (e.g., tubing of ½ inch and less),zero drift was reduced from 100 g/min to 2.5 g/min. Typical minimum flowrate for these sensors is 500 g/min, so the zero drift is reduced toless than 1% of the minimum flow rate. For larger sensors (e.g., ¾ and 1inch tubing), zero drift was reduced from 200 g/min to 25 g/min. Atypical minimum flow rate for these sensors is 6 kg/min, so the zerodrift is reduced to less than 1% of the minimum flow rate.

FIGS. 7-9 show perspective views of additional embodiments of a Coriolisflow sensor 750, 850, 950 and corresponding cradle 700, 800, 900. InFIG. 7 , the flow sensor 750 has a vertical configuration, whereas theflow sensors in previous figures are in-line configurations. In anin-line configuration, the inlet 152 and outlet 156 are in line witheach other, but the flow typically is diverted in order to flow throughthe flow tubes. In a vertical configuration of FIG. 7 , the inlet 752and outlet 756 are not aligned with each other, but the flow is more inline with the flow tubes. The cradle and mounting structure may bedesigned to accommodate multiple different flow sensors, including bothin-line Coriolis flow sensors and vertical Coriolis flow sensors. Inaddition, in FIG. 7 , the locking points 740 are on the corners ratherthan along the sides.

In FIG. 8 , the cradle 800 includes the collar 810 but does not have anenclosure. The flow sensor 850 protrudes through the collar 810 and isvisible below the collar, as shown in FIG. 8B.

In FIG. 9 , the Coriolis flow sensor has an in-line configuration withinlet 952 and outlet 956. It also includes an integrated dampener 962and integrated pressure sensor 964. The dampener 962 is located on theinlet side of the flow sensor. The integrated dampener reducesvibrations in the fluid flow itself, for example as may be caused by apulsating pump. Example dampeners are described in U.S. patentapplication Ser. No. 16/994,611 “Flow Dampener in Flow MeasurementSystem,” which is incorporated by reference in its entirety. Integratingthe dampener and pressure sensor reduces the overall size and spacerequirement, compared to free-standing dampeners and pressure sensorsthat are connected to tubing on the inlet or outlet. It also reduces theamount of tubing required, which in turn reduces the amount of deadvolume. Dead volume is the volume of fluid contained in tubing, sensorsand other components, as this volume is lost and not converted touseable product when the system is flushed between batches. Reducingdead volume is important in pharmaceutical manufacturing, because deadvolume is wasted product, which can be very valuable. The integratedpressure sensor can also produce more accurate pressure readings forcalibrating the Coriolis flow sensor, since it is measuring pressurecloser to the actual flow tubes.

FIG. 10 is a diagram illustrating a flow measurement system 1000 thatuses single-use or disposable flow sensors 1010, 1020, and 1030, asdescribed above. The flow measurement system 1000 also includes twopumps 1013 and 1023, three controllers 1015, 1025, and 1035, threedampeners 1017, 1027, and 1037, and a mixing manifold 1040. The flowmeasurement system 1000 can be a part of a process skid, e.g., abiopharmaceutical or pharmaceutical skid. The pumps 1013, 1023preferably are located close to the flow sensors 1010, 1020 and in-linewith the flow sensors. The dampeners 1017, 1027 are used to mitigatecross-talk from the pumps 1013, 1023 to the flow sensors 1010, 1020,although they may not be required depending on the application.

Two fluids 1050 and 1060 enter the flow measurement system 1000. Onefluid 1050 enters the pump 1013, which pumps the fluid through thedampener 1017 and flow sensor 1010 into the mixing manifold 1040. Theother fluid 1060 enters the pump 1023, which pumps the fluid 1060through the dampener 1027 and flow sensor 1020 into the mixing manifold1040. The flow sensors 1010, 1020 measure flow characteristics (e.g.,mass flow rate, volumetric flow rate, flow density, etc.) of the fluids1050 and 1060, respectively.

The two fluids 1050, 1060 are combined at the mixing manifold 1040, andthe mixture 1070 of the two fluids flows out of the manifold. In someembodiments, the mixing manifold 1040 also receives other fluids ormatter that can be mixed or reacted with fluids 1050 and 1060 to producefluid 1070. The mixing manifold 1040 may include a pump that pumps thefluid 1070 through the dampener 1037 and flow sensor 1030. The flowsensor 1030 measures flow characteristics of fluid 1070.

The flow sensors 1010, 1020, 1030 can operate simultaneously. In someembodiments, at least two of the flow sensors 1010, 1020, and 1030 havesimilar operating ranges. The controllers 1015, 1025, 1035 receivesignals from the flow sensors 1010, 1020, 1030 and conducts flowanalysis based on the signals. The flow analysis includes, for example,determination of flow rate based on signals representing phase shift ofthe flow tubes, determination of flow density based on signalsrepresenting change in resonant frequency of the flow tubes, detectionof bubbles in the fluids based on change in flow density, anddetermination of other flow characteristics of the fluids.

Although the detailed description contains many specifics, these shouldnot be construed as limiting the scope of the invention but merely asillustrating different examples. It should be appreciated that the scopeof the disclosure includes other embodiments not discussed in detailabove. Various other modifications, changes and variations which will beapparent to those skilled in the art may be made in the arrangement,operation and details of the method and apparatus disclosed hereinwithout departing from the spirit and scope as defined in the appendedclaims. Therefore, the scope of the invention should be determined bythe appended claims and their legal equivalents.

What is claimed is:
 1. A Coriolis flow sensor comprising: a flow tubeconstructed from a material with Young's modulus of at least 50 GPa; andan enclosure that encloses the flow tube, the enclosure constructed atleast partially from a gamma transparent material, wherein the gammatransparent material and the flow tube are thin enough to permitsterilization of an interior of the flow tube by gamma irradiation ofthe flow tube through the gamma transparent material; and the enclosureshaped to facilitate locking and unlocking the Coriolis flow sensor inplace on a mounting structure.
 2. The Coriolis flow sensor of claim 1wherein the flow tube is a metal flow tube.
 3. The Coriolis flow sensorof claim 2 wherein the metal flow tube is constructed from a stainlesssteel.
 4. The Coriolis flow sensor of claim 2 wherein the metal flowtube is constructed from Hastelloy, monel, nickel, titanium, ortantalum.
 5. The Coriolis flow sensor of claim 2 wherein the metal flowtube is constructed from a non-magnetic metal.
 6. The Coriolis flowsensor of claim 2 wherein the metal flow tube has a wall thickness notgreater than the wall thickness shown in the following table: Outerdiameter Maximum of flow tube wall thickness (inches) (inches) ¼″ 0.040⅜″ 0.056 ½″ 0.070 ¾″ 0.070 1″ 0.094 2″  0.130.


7. The Coriolis flow sensor of claim 1 wherein the flow tube isconstructed from zirconium.
 8. The Coriolis flow sensor of claim 1wherein the gamma transparent material is plastic or polycarbonate. 9.The Coriolis flow sensor of claim 1 further comprising a gamma stablememory that stores calibration data for the Coriolis flow sensor. 10.The Coriolis flow sensor of claim 1 wherein the Coriolis flow sensor hasan accuracy of +/−1% of a flow rate over an operating range that has aturndown ratio of maximum flow rate to minimum flow rate of at least200.
 11. The Coriolis flow sensor of claim 1 wherein the Coriolis flowsensor is sterilizable by at least one of a clean-in-place process, asteam-in-place process, ethylene oxide cleaning, sodium hydroxidecleaning and x-ray sterilization.
 12. The Coriolis flow sensor of claim1 wherein the Coriolis flow sensor is a disposable, single-use flowsensor.
 13. The Coriolis flow sensor of claim 1 wherein the Coriolisflow sensor is suitable for use in single-use applications, in multi-useapplications and in continuous use applications.
 14. A flow processsystem comprising: a skid for supporting equipment used in anenvironment that includes a flow of fluid; a Coriolis flow sensor formeasuring a flow rate of fluid flow, the Coriolis flow sensorcomprising: a flow tube constructed from a material with Young's modulusof at least 50 GPa; and an enclosure that encloses the flow tube, theenclosure constructed at least partially from a gamma transparentmaterial, wherein the gamma transparent material and the flow tube arethin enough to permit sterilization of an interior of the flow tube bygamma irradiation of the flow tube through the gamma transparentmaterial; a cradle attached to the skid, the cradle having a mountingstructure for the Coriolis flow sensor, wherein the cradle has a mass ofat least ten (10) times a mass of the Coriolis flow sensor and theenclosure is shaped to facilitate locking and unlocking the Coriolisflow sensor in place on the mounting structure; a locking mechanism thatlocks the Coriolis flow sensor in place on the mounting structure,wherein the locking mechanism produces sufficient locking force that theCoriolis flow sensor and cradle vibrate as a unitary body but thelocking mechanism is also unlockable to release the Coriolis flowsensor.
 15. The flow process system of claim 14 wherein: the cradlecomprises a rectangular collar that includes most of the mass of thecradle; and the mounting structure comprises a rectangular annular lipagainst which the Coriolis flow sensor is mounted, the locking mechanismapplying force to the Coriolis flow sensor against the lip.
 16. The flowprocess system of claim 14 wherein the Coriolis flow sensor has a zerodrift of not more than 2.5 g/min.
 17. The flow process system of claim14 wherein the Coriolis flow sensor has a zero drift of not more than 1%of a minimum flow rate measured by the Coriolis flow sensor.
 18. A flowprocess system comprising: a skid for supporting equipment used in anenvironment that includes a flow of fluid; a mixing manifold mounted onthe skid; a first flow path connected to the mixing manifold, and afirst pump and a first Coriolis flow sensor positioned along the firstflow path and mounted on the skid, wherein a first fluid flows throughthe first pump and the first Coriolis flow sensor and into the mixingmanifold; a second flow path connected to the mixing manifold, and asecond pump and a second Coriolis flow sensor positioned along thesecond flow path and mounted on the skid, wherein a second fluid flowsthrough the second pump and the second Coriolis flow sensor and into themixing manifold; and a third flow path connected to the mixing manifold,wherein a third fluid flows out of the mixing manifold, the third fluidcomprising a mixture of the first and second fluids; wherein each of theCoriolis flow sensors comprises: a flow tube constructed from a materialwith Young's modulus of at least 50 GPa; and an enclosure that enclosesthe flow tube, the enclosure constructed at least partially from a gammatransparent material, wherein the gamma transparent material and theflow tube are thin enough to permit sterilization of an interior of theflow tube by gamma irradiation of the flow tube through the gammatransparent material.
 19. The flow process system of claim 18 whereineach of the Coriolis flow sensors is disposable and/or single-use. 20.The flow process system of claim 18 wherein each of the Coriolis flowsensors includes a manually operable locking mechanism that permitsremoval and replacement of the Coriolis flow sensor in one minute orless.